Comparison of balance and proprioception of the shoulder joint in girls with and without upper cross syndrome

Upper cross syndrome is one of the most common disorders of the upper part of body, often associated with abnormalities of forward head, forward shoulders, elevated and protracted of scapula, and increased thoracic kyphosis. Conducting research on upper cross syndrome, especially in girls, is of highly significant, considering this issue and lack of examination of complications and consequences of this syndrome; therefore, this study aims to compare the balance and proprioception of the shoulder joint in girls with and without upper cross syndrome.Method The statistical population included two groups of 10-12-year-old female students, i.e., healthy and those with upper cross syndrome in the city of Khalkhal in Iran in 2022-2023. A total of 60 girl children were included in this study. The subjects were screened using a checker board and after quantitative evaluations of posture, they were assigned into two groups: healthy group (No. 30) and the one suffering from upper cross syndrome (No. 30). Forward head and forward shoulder angle were assessed using photography and kinovea software, kyphosis angle using Goniometer-pro app, static and dynamic balance using BESS and Y tests, also proprioception at angles of 45- and 80-degrees external rotation of the shoulder joint through photography and kinovea software. Data were analyzed through independent t-test in SPSS software version 26 at the significance level of 0.05.Results Healthy girls were in a better position in all variables of static balance (1.14 95% CI: [0.96, 1.70], p = 0.001), dynamic balance (0.81, 95% CI: [0.73,1.24], p = 0.001), proprioception of external rotation of shoulder joint at 45- (0.78, 95% CI: [0.64, 1.14], p = 0.001) and 80-degrees (0.89, 95% CI: [0.59, 1.34], p = 0.001) angles than those with upper cross syndrome.Conclusion It can be concluded that upper cross syndrome causes a decrease in balance and proprioception of the shoulder joint in female students; therefore, along with correcting the abnormalities, special attention should be paid to strengthening and improving these components. It is recommended for rehabilitation professionals to apply exercise training programs to improve the balance and proprioception and correct of the upper cross syndrome: that the strengthening of these components prevents musculoskeletal disorders.Implications for clinical practice• It is recommended for rehabilitation professionals to apply exercise training programs to improve the balance and proprioception of individual with upper cross syndrome.• It is recommended for rehabilitation professionals to apply exercise training programs to correct of the upper cross syndrome in order to prevents musculoskeletal disorders.